Pfannenstiel versus Vertical Skin Incision for Cesarean Delivery in Women with Class III Obesity: A Randomized Trial

Abstract

To compare Pfannenstiel versus vertical skin incision for the prevention of cesarean wound complications in morbidly obese women. Women with body mass index ≥ 40 kg/m2 undergoing cesarean delivery (CD) were randomly allocated to Pfannenstiel or vertical skin incision. The primary outcome was a wound complication within 6 weeks. Due to a low consent rate, we limited enrollment to a defined time period for feasibility. We conducted a traditional frequentist analysis with log-binomial regression to obtain relative risks (RRs), and a Bayesian analysis to estimate the probability of treatment benefit. A priori, we decided that a ≥60% probability of treatment benefit for either incision type would be convincing evidence to pursue a larger trial. A total of 648 women were approached, 228 were consented, and 91 were randomized. The primary outcome rate was 19% in the Pfannenstiel group and 21% in the vertical group (RR: 1.18; 95% confidence interval: 0.49-2.85). Bayesian analysis revealed a 59% probability that Pfannenstiel had a lower primary outcome rate. In the first published randomized trial to compare skin incision types for obese women undergoing CD, we were unable to demonstrate differences in clinical outcomes. Our trial suggests that a larger study would have a low probability for different findings. NCT 01897376 (www.clinicaltrials.gov).